#include <regex>
#include <string>
#include <iostream>

int main(){
    std::string str = "/hello/html/1234";

    std::regex ex("/hello/html/(\\d+)");

    std::smatch matches;
    
    bool ret = std::regex_match(str, matches, ex);
    if(ret == false){
        return -1;
    }
    for(auto &s : matches){
        std::cout << s << std::endl;
    }
    return 0;
}